Messages in this thread Patch in this message | | | From | Yoshinori Sato <> | Subject | [PATCH v3] asm-generic: {get,put}_user ptr argument evaluate only 1 time | Date | Tue, 21 Jul 2015 15:14:49 +0900 |
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Current implemantation ptr argument evaluate 2 times. It'll be an unexpected result.
Changes v3: Some build error fix. Changes v2: Argument x protect.
Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp> --- include/asm-generic/uaccess.h | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h index 72d8803..d800a3f 100644 --- a/include/asm-generic/uaccess.h +++ b/include/asm-generic/uaccess.h @@ -163,9 +163,10 @@ static inline __must_check long __copy_to_user(void __user *to, #define put_user(x, ptr) \ ({ \ + uintptr_t __uip = (uintptr_t)(ptr); \ might_fault(); \ - access_ok(VERIFY_WRITE, ptr, sizeof(*ptr)) ? \ - __put_user(x, ptr) : \ + access_ok(VERIFY_WRITE, __uip, sizeof(*ptr)) ? \ + __put_user((x), ((__typeof__(*ptr) *)__uip)) : \ -EFAULT; \ }) @@ -225,9 +226,10 @@ extern int __put_user_bad(void) __attribute__((noreturn)); #define get_user(x, ptr) \ ({ \ + uintptr_t __uip = (uintptr_t)(ptr); \ might_fault(); \ - access_ok(VERIFY_READ, ptr, sizeof(*ptr)) ? \ - __get_user(x, ptr) : \ + access_ok(VERIFY_READ, __uip, sizeof(*ptr)) ? \ + __get_user((x), (__typeof__(*ptr) *)__uip) : \ -EFAULT; \ }) -- 2.1.4
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